Saturday, April 12, 2008

A Not So Cool Superconductor

A group of researchers at Indiana University have made an interesting discovery. They have found what looks to be superconducting behaviour in small clusters of aluminum (45 and 47 atoms of aluminum) with a critical temperature of around 200K (-73 degrees Celsius). The observed behaviour is a peak in the heat capacity of the clusters which is indicative of superconductivity. Such indirect tests are required because ordinary ideas of what superconductivity means break down when you only have 45 atoms involved.

This is pretty cool, but don't expect any real world applications any time soon. This high temperature superconductivity only works because of the very small size of the clusters. Change the size of the cluster by one atom and it goes away. We might be able to make a series of these clusters and weakly link them, but that is beyond the capabilities at the present moment.

Finally, although it in no way contributed to this work, I'd like to link to my honours thesis which was entitled "Superconducting correlations in metallic nanoparticles". Unfortunately, I don't have a copy on my computer here or anywhere on the web so I can't.